"the rachel maddow show" starts right now. ezra klein is filling in for rachel tonight. not django. good evening, ezra. >> good evening, michael. thank you very much. and thank you to you at home for sticking around for the next hour. rachel has a well-deserved night off. but today on the senate there was a rare sighting on the senate floor. especially around this time of year. right now the senate is usually a bit of a desolate place, but today at exactly 2:34 p.m. eastern standard time there was something big afoot. at 2:34 this afternoon in from the wings of the chamber walked the president of the senate, vice president joe biden. joe biden does not often serve in his capacity as president of the senate. but today was ditch. today joe biden had an incredibly important job to fulfill. >> do you solemnly swear to support and defend the constitution of the united states against all enemies, foreign and domestic, that you will bear true faith and allegiance to the same, that you take this obligation freely without any mental reservation or purpose of evasion, and that you will well a